葡萄多酚改善高脂饮食诱导的小鼠高血脂及对肠道菌群的调节作用

以C57BL/6雄性小鼠建立高血脂模型,研究葡萄多酚干预下小鼠的体重、血脂等指标的变化,应用16S RNA高通量测序技术检测了多酚干预下高血脂小鼠肠道菌群的变化。结果表明:葡萄皮渣多酚提取物(GPE)和葡萄原花青素(GSE)能显著抑制高脂饮食C57BL/6J小鼠的体重增加。GPE灌胃8周能显著降低LDL-c水平;GSE则可显著降低TG、TC、LDL-c水平,表明GPE和GSE能改善高脂饮食小鼠的脂质紊乱并表现出降血脂,改善肝脏脂质累积的效果。通过分析多酚干预下高脂饮食小鼠肠道菌群的变化,发现GPE、GSE具有调节高脂饮食介导的肠道菌群紊乱的功能,并且这可能与其改善脂质代谢的作用相关。     

饮食结构、营养成分对抑郁症的影响研究进展

抑郁症正在成为仅次于癌症的人类第二大杀手,全球预计有3.4亿 人患病。研究报道表明通过饮食可以干预抑郁。本文综述了高蛋白饮食、素食饮食、高脂饮食和生酮饮食等饮食结构对抑郁症的影响作用,讨论了食物中叶酸、膳食纤维、多酚化合物、维生素和多不饱和脂肪酸等营养成分对抑郁症状的改善作用,并总结了饮食结构与营养成分通过调节单胺类神经递质代谢、消化道与肠道菌群、神经内分泌系统等3 种作用机制进而影响抑郁。本文可为从饮食上预防和干涉抑郁症提供新的思路。     

发芽绿豆多酚的降血糖作用及对糖尿病小鼠肠道菌群的影响

目的:探究发芽绿豆多酚提取物对2型糖尿病小鼠的降血糖效果以及对小鼠肠道菌群的影响。方法:根据C57BL/6小鼠体质量,随机分为正常组、T2DM模型组、阳性对照组、发芽绿豆多酚提取物低(50 mg/kg)、中(100 mg/kg)、高(150 mg/kg)剂量组,通过高脂饮食联合腹腔注射链脲佐菌素(STZ)的方法,建立2型糖尿病小鼠模型。灌胃5周后测定小鼠空腹血糖(FBG)、葡萄糖耐量、胰岛素(INS)以及炎症因子白细胞介素IL-6、IL-10、肿瘤坏死因子(TNF-α)、C反应蛋白(CRP)的浓度。收集小鼠粪便,应用16S rRNA平台进行高通量测序,检测多酚提取物干预下糖尿病小鼠肠道菌群的变化。结果:发芽绿豆多酚提取物能够显著降低T2DM小鼠的空腹血糖值,提高葡萄糖耐量水平,降低胰岛素抵抗;显著降低IL-6、TNF-α、CPR的水平,升高IL-10水平,进而缓解糖尿病引起的炎症反应;修复小鼠肝脏组织细胞形态;调节菌群丰度及物种多样性,改善失调的肠道菌群。结论:发芽绿豆多酚提取物通过减轻炎症反应和调节肠道菌群的丰度来改善小鼠的2型糖尿病。     

黑果腺肋花楸汁对便秘小鼠肠道功能的改善作用

为研究黑果腺肋花楸汁改善小鼠便秘,维护肠道健康的作用,将小鼠分为5组:空白对照组、便秘模型对照组、黑果腺肋花楸汁低、中、高剂量组,用样品干预14 d后通过盐酸洛哌丁胺造便秘模型,测定各组小鼠的排便功能、肠道运动、胃肠调节肽指标和16S rRNA肠道菌群指标。结果显示:便秘模型成立,黑果腺肋花楸汁可以缩短首粒黑便排出时间,增加5 h内排便粒数和质量,提高小肠墨汁推进率,促进胃泌素(Gas)、胃动素(MTL)和P物质(SP)含量,降低生长抑素(SS)、内皮素(ET-1)和血管活性肠肽(VIP)含量,且具有一定的剂量相关性。此外,黑果腺肋花楸汁在一定程度上可改变肠道菌群的分布,丰富物种的丰度,显著降低厚壁菌门与拟杆菌门相对丰度比值(F/B),降低便秘小鼠变形菌门、葡萄球菌属的丰度。研究表明黑果腺肋花楸汁对盐酸罗哌丁胺诱导的便秘小鼠有通便作用,其机制是通过调节肠道激素的分泌和肠道菌群结构来改善便秘症状。     

藤茶多酚对小鼠衰老过程中骨质代谢及肠道菌群的影响

肠道菌群对于宿主健康起着至关重要的作用,与衰老过程中骨质代谢紊乱息息相关。作者旨在研究以长寿特性而闻名的巴马藤茶对小鼠衰老进程中骨质代谢的影响,以评估藤茶多酚改善衰老小鼠肠道菌群结构的潜力。结果表明,藤茶多酚可以上调小鼠肝脏中的超氧化物歧化酶、谷胱甘肽和总抗氧化力水平,下调丙二醛水平。同时,藤茶多酚能够通过改善小鼠衰老过程中的骨质代谢,上调Osterix基因的表达,降低Acp5的表达,从而促进骨形成、减少骨吸收。此外,藤茶多酚可以调节衰老小鼠的肠道菌群组成,促进粪便中乙酸、丙酸和丁酸的产生。总之,藤茶多酚可以作为一种益生元,减少衰老过程中的骨质流失并调节肠道菌群,从而达到延缓衰老的目的。     

基于肠道菌群的黑果腺肋花楸多酚降压作用初探

以黑果腺肋花楸多酚（AMP）为原料,探究其对高盐、高糖饮食所致高血压大鼠模型的血压调节及肠道菌群的影响。对Waster大鼠进行20%果糖饮水和5% NaCl喂养试验21 d,结束后取其粪便进行肠道菌群丰富度分析、菌群群落分析、Heatmap分析、COG数据库对比分析。结果显示,AMP对高血压的降压效果显著,且降压效果不是单纯的随浓度的升高而升高,其中AMP中剂量组（质量浓度为1.4 mg/kg,每日灌胃剂量7.5 mL/kg）的降压效果最好,降压达11.6%。AMP不仅能调节肠道菌群微环境,还对高血压大鼠的肠道功能有较好的改善作用,有利于提高降压效果。与常规降压药相比,AMP对肠道菌群影响小,且可增加一些有益菌丰富度,如乳酸菌较正常组提高59.2％。本研究结果为AMP作为调节高血压的功能性因子,制备相关功能性食品提供理论依据。     

肠道菌群与抑郁症相关性的研究进展

抑郁症是一种常见的精神疾病,通常与性别、遗传、环境或心理原因有关。肠道菌群可参与人体的众多生理调节,对情绪状态和行为认知方面发挥重要作用。健康的肠道微生物群主要以拟杆菌门和厚壁菌门为主要优势菌门,而抑郁症患者的肠道微生物丰富度和多样性较正常人相比显著降低。研究发现肠道微生物群通过神经、免疫和代谢途径直接或间接与大脑进行双向沟通,肠道菌群变化与抑郁症之间存在明显的相关性。因此,保持健康的肠道微生物群对大脑健康极其重要。该研究主要基于肠-脑轴探讨抑郁症的可能发病机制,分别从肠道菌群影响单胺类神经递质的产生、改变神经系统可塑性、诱使炎症因子水平变化以及导致下丘脑-垂体-肾上腺轴功能紊乱等4个方面对抑郁症的作用进行讨论。此外,该研究还总结了几种调节肠道菌群干预抑郁症的可能途径,以期为治疗抑郁症提供新的思路。     

酸枣仁皂苷A对抑郁小鼠行为及突触可塑性相关蛋白的作用

该文探究了酸枣仁皂苷A（Jujuboside A,JuA）对抑郁模型小鼠行为及神经突触可塑性相关蛋白表达的作用。通过悬尾实验、强迫游泳实验、旷场实验、Morris水迷宫实验评价小鼠的抑郁状态,免疫组织化学染色法检测小鼠海马组织中脑源性神经营养因子（Brain Derived Neurotrophic Factor,BDNF）的表达水平,Western blot实验检测小鼠海马组织酪氨酸激酶受体B（Tyrosine Kinase Receptor B,TrkB）、cAMP反应元件结合蛋白（cAMP Responsive Element Binding,CREB）、突触后密度蛋白95（Postsynaptic Density Protein 95,PSD95）、自噬效应蛋白Beclin1（Autophagy Effector Protein Beclin1,Beclin1）的表达水平。结果表明,JuA显著改善抑郁模型小鼠的抑郁状态。同时,JuA作用后海马组织BDNF、TrkB、CREB、PSD95、Beclin1的表达水平较模型组分别上调了190.23%、137.24%、76.29%、169.32%、82.53%。综上所述,JuA对抑郁模型小鼠具有显著的抗抑郁作用,并能明上调BDNF、TrkB、CREB、PSD95、Beclin1等神经突触可塑性相关蛋白的表达。实验结果为JuA在抑郁症临床治疗方面的应用提供理论依据,并为探究抑郁症药物治疗靶点提供参考。     

海红米米糠对慢性应激诱导小鼠抑郁样行为和异常肠道微生物及神经递质的改善作用

“微生物-肠-脑轴”失常在抑郁症的发病中发挥着重要作用,调节肠道菌群失衡成为最新的治疗方向。海红米皮可发挥益生元作用调控肠道微生物。本实验目的为探究海红米皮改善慢性不可预测温和应激(CUMS)诱导的小鼠抑郁样行为的作用。对照和暴露于CUMS的小鼠接受正常或含5%海红米皮饮食喂养9周,通过糖水偏好实验和悬尾实验分析小鼠的抑郁样行为,实时荧光定量PCR法检测结肠内容物菌群的数量,HPLC测定前额皮层中单胺类神经递质的含量。应激使小鼠糖水偏好度、乳杆菌属和双歧杆菌属的数量、去甲肾上腺素(NE)与其代谢产物、五羟色胺(5-HT)与其代谢产物、多巴胺(DA)与其代谢产物的含量都显著下降,悬尾不动时间和梭菌属的数量都显著升高；海红米皮干预后提高了小鼠的糖水偏好度、乳杆菌属和双歧杆菌属的数量、5-HT与其代谢产物和NE的含量,降低了悬尾不动时间。海红米皮改善CUMS诱导的小鼠抑郁样行为可能与改善肠道菌群失衡及神经递质有关。     

植物多酚改善肠道屏障及糖脂代谢的研究进展

植物多酚是植物的次级代谢产物,广泛存在于水果、蔬菜、茶和谷物中,大量研究表明植物多酚能够与肠道菌群发生相互作用,通过直接调节或产生代谢产物间接刺激对肠道微生物的菌群结构进行正向调节,在稳定血糖血脂、改善胰岛素敏感性、改善肠道功能以及调节糖脂代谢方面发挥重要作用。该文主要综述植物多酚与肠道菌群的相互作用,及其通过调控肠道菌群改善肠道屏障功能及糖脂代谢紊乱的作用机制,并对其应用前景进行展望,以期为深度开发植物多酚提供科学依据,为促进肠道健康和防治糖尿病、肥胖等代谢疾病提供参考。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.